My new compact S&W M&P 9mm has a tactical rail that is too short to lock in my tactical light/laser sight. It slides on firmly but does not lock on. I am afraid to shoot the gun in this situation, fearing a loss of the light as it flies off the rail. I have heard about these Crimson Trace grip laser sights.They appear to be easily added to my gun and would solve my immediate problem but I wonder about others experience with the product. Any advice, pro or con? If pro, any advice on the best price available on the product? If con, any advice on competing products? Thanks in advance for your help with my problem.